In recent years, with a continuous increase in power of a communications device and a requirement for being energy-efficient in the communications industry, a high-voltage direct current High-Voltage Direct Current (HVDC) power supply is gradually used to supply power to a data center and a communications equipment room. Therefore, an HVDC technology is developing rapidly in the communications field.
However, as power supply voltages in the data center and the communications equipment room increase, when a load branch connected using a power supply link short-circuits, short circuit currents in the load branch and the power supply link also continuously increase. An excessively high short circuit current may cause a power outage in some important communications devices.